But many were left disappointed after she refused to walk the full length of a specially themed black carpet, and then went inside before some had even seen her, leading to a chorus of boos.

Luke Reader, 18, from central London, said: "It's quite ironic it's called Fame because it just shows how much fame has changed her. She couldn't even spend five minutes talking and having some pictures taken. It's not on."

Lauren Weymouth, 19, waited for five hours to see the American star. "I'm disappointed," the Australian holidaymaker said. "I thought she'd stand there for a while, but we didn't see anything."

Gaga's fans - known as Little Monsters - held black and gold balloons and sang a number of her hits including Bad Romance and Poker Face as they waited for the star. She was due to arrive at the event in Knightsbridge, central London, at 7.30pm, but it was 8.45pm before she finally turned up - wearing a black dress - in a horse and carriage.

She then walked part of the way down the black carpet before entering the store where she held a tea party for 75 competition winners. Music was provided by her friend DJ White Shadow, while the lucky guests ate black macaroons.

The Born This Way star did not speak to the media, but earlier wrote on Twitter: "So excited, going to be at @Harrods in an hour! Just drove though London, so beautiful seeing all the Sunday strollers in love..."